diff --git a/pkgs/development/python-modules/pgpy/default.nix b/pkgs/development/python-modules/pgpy/default.nix
index d9366a75427687..7d7222477b746d 100644
--- a/pkgs/development/python-modules/pgpy/default.nix
+++ b/pkgs/development/python-modules/pgpy/default.nix
@@ -7,6 +7,7 @@
   pyasn1,
   cryptography,
   pytestCheckHook,
+  standard-imghdr,
 }:
 
 buildPythonPackage rec {
@@ -15,7 +16,7 @@ buildPythonPackage rec {
 
   disabled = pythonOlder "3.6";
 
-  format = "pyproject";
+  pyproject = true;
 
   src = fetchFromGitHub {
     owner = "SecurityInnovation";
@@ -24,24 +25,30 @@ buildPythonPackage rec {
     hash = "sha256-47YiHNxmjyCOYHHUV3Zyhs3Att9HZtCXYfbN34ooTxU=";
   };
 
-  nativeBuildInputs = [ setuptools ];
+  build-system = [ setuptools ];
 
-  propagatedBuildInputs = [
+  dependencies = [
     pyasn1
+    standard-imghdr
     cryptography
   ];
 
+  postPatch = ''
+    substituteInPlace tests/test_10_exceptions.py \ # https://github.com/SecurityInnovation/PGPy/issues/472
+      --replace-fail ", 512" ", 1024" # We need longer test key because pgp deprecated length=512
+  '';
+
   nativeCheckInputs = [ pytestCheckHook ];
 
-  meta = with lib; {
+  meta = {
     homepage = "https://github.com/SecurityInnovation/PGPy";
     description = "Pretty Good Privacy for Python";
     longDescription = ''
       PGPy is a Python library for implementing Pretty Good Privacy into Python
       programs, conforming to the OpenPGP specification per RFC 4880.
     '';
-    license = licenses.bsd3;
-    maintainers = with maintainers; [
+    license = lib.licenses.bsd3;
+    maintainers = with lib.maintainers; [
       eadwu
       dotlambda
     ];